title: Advanced parental age and the risk of autism spectrum disorder.
abstract: This study evaluated independent effects of maternal and paternal age on risk of autism spectrum disorder. A case-cohort design was implemented using data from 10 US study sites participating in the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network. The 1994 birth cohort included 253,347 study-site births with complete parental age information. Cases included 1,251 children aged 8 years with complete parental age information from the same birth cohort and identified as having an autism spectrum disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. After adjustment for the other parent's age, birth order, maternal education, and other covariates, both maternal and paternal age were independently associated with autism (adjusted odds ratio for maternal age > or =35 vs. 25-29 years = 1.3, 95% confidence interval: 1.1, 1.6; adjusted odds ratio for paternal age > or =40 years vs. 25-29 years = 1.4, 95% confidence interval: 1.1, 1.8). Firstborn offspring of 2 older parents were 3 times more likely to develop autism than were third- or later-born offspring of mothers aged 20-34 years and fathers aged <40 years (odds ratio = 3.1, 95% confidence interval: 2.0, 4.7). The increase in autism risk with both maternal and paternal age has potential implications for public health planning and investigations of autism etiology.
authors.affiliation: Waisman Center, University of Wisconsin School of Medicine and Public Health, 789 WARF, 610 Walnut Street, Madison, WI 53726, USA. mdurkin@wisc.edu
authors.forename: Maureen S
authors.initials: MS
authors.lastname: Durkin
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Maenner
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Newschaffer
authors.forename: Li-Ching
authors.initials: LC
authors.lastname: Lee
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Cunniff
authors.forename: Julie L
authors.initials: JL
authors.lastname: Daniels
authors.forename: Russell S
authors.initials: RS
authors.lastname: Kirby
authors.forename: Lewis
authors.initials: L
authors.lastname: Leavitt
authors.forename: Lisa
authors.initials: L
authors.lastname: Miller
authors.forename: Walter
authors.initials: W
authors.lastname: Zahorodny
authors.forename: Laura A
authors.initials: LA
authors.lastname: Schieve
mesh_terms: D000328:Adult; D001321:Autistic Disorder / Q000453:epidemiology* / Q000209:etiology; D001722:Birth Order; D016022:Case-Control Studies; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology; D015331:Cohort Studies; D016001:Confidence Intervals; D005220:Fathers; D005260:Female; D006801:Humans; D008297:Male; D009035:Mothers; D016017:Odds Ratio; D010290:Parents; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology